Infragistics UltraGrid - how to add rows when scroll reaches bottom?

Question

I have a table with 100,000 records and i have a method (using entity framework) that retrieve 10 records, i give it how many records skip to get the next 10 records.

List<Item> GetRecords(int skip = 0);

I load the first 10 records on a list, and set it as datasource of the UltraGrid, how can i call the method to get the next 10 records and add it to the UltraGrid when the scroll reaches the bottom or is near to reach the bottom?

Answer 1

I have a solution for your requirement. Hope this helps you..

First, create a windows form named "test" (say).. Add a ultraGrid in the form..

check the following code:

   public partial class test : Form
   {
    DataTable dtSource = new DataTable();
    int takecount = 50;
    int skipcount = 0;
    DataTable dtResult;

    // CONSTRUCTOR
    public test()
    {
        InitializeComponent();

        // Fill Dummy data here as datasource...

        dtSource.Columns.Add("SNo", typeof(int));
        dtSource.Columns.Add("Name", typeof(string));
        dtSource.Columns.Add("Address", typeof(string));
        int i = 1;
        while (i <= 500)
        {               
            dtSource.Rows.Add(new object[] { i, "Name: " + i, "Address " + i });
            i++;
        }
        dtResult = dtSource.Copy();
        dtResult.Clear();
    }

    // ON FORM LOAD FUNCTION CALL
    private void test_Load(object sender, EventArgs e)
    {            
        ultraGrid1.DataSource = dt_takeCount();
        ultraGrid1.DataBind();


    }

    private DataTable dt_takeCount()
    {            
        if (dtSource.Rows.Count - skipcount <= takecount)
        {
            takecount = dtSource.Rows.Count - skipcount;
        }
        foreach (var item in dtSource.AsEnumerable().Skip(skipcount).Take(takecount))
        {
            dtResult.Rows.Add(new object[] { item.Field<int>("SNo"), item.Field<string>("Name"), item.Field<string>("Address") });
        }
        if (dtSource.Rows.Count - skipcount >= takecount)
        {
            skipcount += takecount;               
        }            
        return dtResult;
    }

    // EVENT FIRED WHEN ON AFTERROWREGIONSCROLL
    private void ultraGrid1_AfterRowRegionScroll(object sender, Infragistics.Win.UltraWinGrid.RowScrollRegionEventArgs e)
    {
        int _pos = e.RowScrollRegion.ScrollPosition;
        if (ultraGrid1.Rows.Count - _pos < takecount)
        {
            dt_takeCount();
        }           
    }        
}

Above code is all that works.. --> "ultraGrid1_AfterRowRegionScroll" function is "AfterRowRegionScroll" event function

--> But be sure that when you choose "takecount", it generates scrollbar, --> when you run above code... the row will be updated by 50 when you scroll,, till 500th row.. because it is the last row.